NさえVerbば
Usage
Nounさえ with a verb conditional form is used when the condition presented in the clause is the only condition to make the statement in the main clause true. さえ replaces the particles が and を in this structure. When other particles are used the stay though.
Examples
私は、愛さえあれば幸せです。
If only I could have love I would be happy.
いい友達さえいれば、ほかに欲しいものはありません。
If I just could have good friends, then I would want nothing else.